Because of the large number of leads of such components as micro processors and application specific integrated circuits, each of which leads is connected to an external contact pad on a surface of the component, the problem arises of providing reliable mating interfaces between the pads and the circuit board, within the bounds of commercial viability. Although according to the teaching of U.S. Pat. No. 4,511,197, U.S. Pat. No. 4,513,353 and U.S. Pat. No. 4,699,593, there can be interposed between an electronic component and a circuit board, an electrical connector assembly comprising a plurality of spring contact elements each for engagement with a pad on the electronic component and a pad on the circuit board, a gold finish is needed on the pads of the circuit board, especially where high speed electronic components are concerned. The provision of such a gold finish by means of electroplating is undesirably expensive and a pin hole free, pore free, gold surface is not necessarily always achievable.